Preparation of vegetable gum solutions



Patented an. 17, 1939 v 2,144,522

v UNITED ,,STAT,E S PATENT OFFICE 1 v 12,144,522 1 ,jraEPARATIoN FVEGETABLE GUM I V, v SOLUTIONS E Robert'O. 'Braun, Clifton, N. J.,assignor to Jacques Wolf & 00., Passaic, N. J., a corporation of;NewJersey No Drawing. Application July 26, 193-1,

Serial No. 155,694

2 Claims. (Cl. 8'72) This invention relates to the preparation of I havediscovered that it is indispensable to the vegetable gum solutions,forinstance, those removal of the color to have the activated carbon formedof gum shiraz, gum karaya, the locust present in some way in thewater-and-gum mixbean gum or any of various other vegetable gums tu rebefore the solubilizing is initiated. The in raw state, or ofcombinations of 'difierent raw quantity of such activated carbon may befrom 5, vegetable gums,and more particularly to such 1 to percent of thetotal amount of gum and preparation where, following solubilizing of thewater present (by weight) where they are in the gum, concentration ofthe gum solution is efiected proportions 1 to 9 (by weight).

so that the concentrated gum solution may be In respect to mysecond-named object I have 10 useful, for instance, as a thickener inthe printfound that if aluminum sulphate is made tobe 1o ing oftextiles. present with the activated carbon and hence with One object ofthe invention is to prepare soluthe sodium sulphate associated therewiththere tions of vegetable gums so as to have them de- Will not only beelimination of color but alessenvoid or substantially completelydeprived of color., ing of the cloudiness in the concentrated sum This Iaccomplished by the use ofv activated ear-v solution, and that if notless than a certainls bon of commerce (now well known as adecolorizquantity of such aluminum sulphate be present ing agent, forinstance, in the decolorizing of oils, there will be a definitelycomplete lack of cloudlfats and glycerine) but only by such use in theness. Further, that such gum solution will be particular way hereinafterset forth. The colordistinctly long-bodied. mg matter is absorbed by theactivated carbon, I a u for t mp v m nt as o la ty 20 which isultimately removed by filtering. as follows: If sodium sulphate andaluminum But although I haveaccomplished this object sulphate arecrystallized byconcentration out of I have found that when activatedcarbon alone a solution in which both are present they com- I is usedthe gum solution on being concentrated bine to form aluminum-sodiumsulphate, a 5 will nevertheless usually be cloudy instead of double saltthe solubility of which in the conclear. This cloudy condition is due tothe centrated gum solution is about ten times as presence in theactivated carbon of certain salts, great as that of sodium sulphate(which, per se,': notably sodium sulphate (usually present in ispractically insoluble in such solution). As for amounts varying from oneto eight percent) t o -b d ed Co d io o the ult a umwhich goes intosolution 'when the gum is solution, the complicated chemical composition30 solubilized, as withth'e aid of heat, but is preof ese ve e ab s dsolutions thereof is cipitated out and becomes suspended when the notsufiiciently known to afford a definite exgum solution is concentratedby evaporation, planation; I however make this observation: that withincidental cooling, to the state ready for it is known that somealkalis, such as borax,

use. completely change their body, and apparently 35 Further, whenactivated carbon alone is used either aluminum Su p te, or the double slt s the concentrated gum solution will also be shortsequently formed,likewise actsb died instead of long-bodied. A long-bodied The chemicalformula forthe said double salt as distinguished from a short-bodiedconis AlNa(SO4)z-l2HzO, which may also be written 4o centrated'gumsolution 'isone which, when drawn Al 2(SO4)a-Na2SO424I-I2O. This showsthatv the 40 up from the solution by a glass stirring rod two sulphatescombine to form the double salt dipped therein, will flow' back ratherthan drip in the ratio of 2.4 parts of aluminum sulphate orintermittently fall back into the solution until to 1 part of sodiumsulphate. practically all of the liquid so drawn up has re- Hence,having by analysis determined the turned. amount of sodium sulphateassociated with the 45 A further object of the invention, therefore, isactivated carbon, I cause to be present in the to produce a concentratedvegetable gum soluwater, gum and activated carbon mixture, before tionwhich will be not only devoid or substantially the concentration step,enough aluminum suldeprived of color, but which will be cloudless; phateso that there will-be at least 2.4 parts and in accomplishment of thisobject I have thereof to each partjof sodium sulphate, by 50 found thata long-bodied as distinguished from weight. According as the aluminumsulphate is a short-bodied concentrated gum solution results. less thanthe indicated quantity so the cloudiness Now in respect to myfirst-mentioned object, will be greater and the ultimate solution whileothers have attempted to remove the color shorter bodied. A greaterquantity, however,

by the use of activated carbon without success, leaves the solutionstill cloudless and long-bcdied.

It is not material when the aluminum sulphate is introduced except thatit should be at some time before the concentration of the solution iseffected After the solubilizing the gum solution may be filtered andthen concentrated in the,

usual Way, by evaporation.

For thepurpose of this specification the term "activated carbon" is usedto mean the activated carbon of commerce, i. e., contaminated bypresence of sodium sulphate.

Having thus fully described my invention what I claim is: I

l. The herein-described method of preparing a concentrated solution froma raw vegetable gum which consists in forming a mixture of the gum andwater, thereupon solubilizing the gum in the water of such mixturehaving already caused the herein-defined activated carbon to be presentin the mixture, and, having already caused alucaused aluminum sulphateto be present with the water, gum and such carbon in the propor-V -tion,bylweight, of not less than 2.4 parts of such aluminum sulphate to 1part of the sodium sulphate associated with the carbon, thereuponseparating the carbon from and concentrating the solution formed.

ROBERT C. BRAUN.

